Cam-driven, automated assembly apparatus are becoming more prevalent in industrial assembly applications. One type of automated assembly device is the so-called linear pick-and-place device. Its output is pre-designed, via specific cam design selection, to provide both vertical and horizontal movements to its output, and any associated end effector member, e.g., a pick-up device or robot hand. The resultant output is both in and out, as well as up and down, thereby allowing various types of motion sequences for assembly applications, dependant upon what cam design is used. For example, with such a linear pick-and-place device, a part can be picked up at one location, moved vertically, horizontally transferred over to another location, and then dropped vertically in place, such as in an associated tooling station or die set, whereafter the sequence is repeated for the next part.
The known linear pick-and-place devices of the prior art typically use a movable carriage device, driven by associated cam members, which carriage typically has two hardened and grounded output shafts which slide upon and within multiple bearing assemblies carried by the carriage. Such ground multiple output shaft arrangements are known in the industry as Thompson (Trademark) shafts. See, for example, U.S. Pat. No. 3,881,362, which typifies this type of linear pick-and-place device.
The movable carriage units for such known linear pick-and-place devices are cumbersome and costly. Also, all the known designs of prior art linear pick-and-place devices suffer the disadvantage of having their output member aligned off-center from the unit's input shaft. This is due to interference of the multiple shaft carriage unit with the cam members if the former is placed in centered alignment with the latter. Inherently, such designs are relatively wide. Therefore, in many applications, such as where multiple linear pick-and-place devices need to be aligned in side-by-side parallel fashion for a given assembly application, they are often unusable.
The present invention overcomes these difficulties by utilizing, in the drive of a linear pick-and-place apparatus, a unique guide track assembly for the movable carriage. A series of V-rollers and mating V-tracks are used for both the vertical and horizontal (i.e., translation) movements of the apparatus' output member. Further, the V-track assembly utilizes V-roller elements which can be eccentrically adjusted to affect a tight, i.e., pre-loaded,. sliding engagement with the mating V-tracks. Thereby, substantially all undesired end play movement within the movable carriage is eliminated, in both the vertical and horizontal directions.
Thus, it is an object of the present invention to provide an improved drive for a linear pick-and-place device which utilizes a V-track and V-roller assembly to result in a stiffer design resulting in greater accuracy in picking and placing of parts and which permits centerline alignment of the device's input and output members.
It is another object of the present invention to utilize a V-roller and V-track carriage assembly for a linear pick-and-place device which substantially eliminates all end play during vertical and horizontal translation movements of the device's output member.